Abstract Linear and nonlinear Finite Element (FE) analyses and experimental work on local buckling of un-stiffened, fully stiffened and partially stiffened full scale pultruded GRP profiles under uniform axial compression are presented. An investigation on improving the buckling capacity of I-section pultruded profile by bonding high modulus unidirectional CFRP strips to the top and bottom surface of the flanges along their free edges is carried out. The experimental buckling load for short columns with clamped ends (CC) have been evaluated using Southwell plots of deflection and bending strain test data. The experimental buckling loads have been also evaluated using the load versus end-shortening graphs. The predicted buckling loads obtained from FE analyses are compared with the experimental results and good agreement has been achieved. It has been shown that, the use of stiffeners generally produces a significant increase in the local buckling load and a significant shift in the buckling mode.